.list .item {
    height: 30px;
    width: 100%;
    border: 1px solid #ccc;
    margin: 3px 0;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.delDutton {
    display: none;
}

.item:hover {
    background: red;
}

.item:hover .delDutton {
    display: block;
}